<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      html,
      body {
        width: 100%;
        height: 100%;
      }

      * {
        margin: 0;
      }

      .container {
        display: flex;
        height: 100%;
      }
      .left {
        width: 300px;
        background-color: red;
      }
      .right {
        flex: 1;
        background: orange;
        overflow: auto;
      }
      .right div {
        width: 300px;
        height: 300px;
        border: 1px black solid;
      }
    </style>
  </head>
  <body>
    <div class="container">
      <input type="text" id="demo">
      <div class="left">left</div>
      <div class="right">
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
      </div>
    </div>
    <script>
      const demo = document.querySelector('input');
      console.log(demo);
      demo.addEventListener('change', () => {
        console.log('change');
      })
      demo.addEventListener('compositionstart', () => {
        console.log('compositionStart');
      })
      demo.addEventListener('compositionupdate', () => {
        console.log('compositionUpdate');
      })
      demo.addEventListener('compositionend', () => {
        console.log('compositionEnd');
      })
    </script>
  </body>
</html>
